The invention relates to a two-stroke engine of the type having a cylinder, in which a combustion chamber is formed, wherein the combustion chamber is bounded by a piston which drives a crankshaft mounted rotatably in a crankcase, wherein the crankcase is connected, via at least one overflow passage, to the combustion chamber when the piston is in the region of its lower dead center, with an air-fuel mixture passage which opens into the crankcase and which is guided in an intake passage, for supplying fuel and combustion air and into which fuel is supplied via at least one fuel opening, and wherein at least one section of the mixture passage is guided in a connecting stub.
DE 10 2007 037 009 A1 discloses a connecting stub for a two-stroke engine, the intake passage of which is divided into an air passage and a mixture passage.
It has been shown that, in particular during idling, the running behavior in a two-stroke engine of this type may be inadequate because fuel can accumulate in the connecting stub and is then supplied to the crankcase in an undefined manner. Dead regions in the connecting stub, in which there is insufficient flow of air, may also cause fuel to accumulate, the fuel then not being available to the internal combustion engine.
It is known to provide the connecting stub with grooves which conduct the fuel accumulated in the connecting stub away to the crankcase. Structures, in which fuel can accumulate, such as pyramid-shaped elevations or ribs running in the circumferential direction, are also known.